added ram disk status message on startup screen

src/dos_m65/,aliases_dos.s

@@ -32,7 +32,7 @@
 	!addr RAM_ATTIC        = $8009 ; $8000000-$87FFFFF RAM status; 0 = not present, $FF = present
 	!addr RAM_CELLAR       = $800A ; $8800000-$8FFFFFF RAM status; 0 = not present, $FF = present
 
-	; Reserved: $800B
+	!addr RD_MSG           = $800B ; code of the RAM disk message to be displayed on banner screen, $FF for none
 
 	; General DOS configuration
 

src/dos_m65/4020.dos_vectable.s

@@ -3,6 +3,7 @@
 
 !word dos_INIT
 !word dos_PRELOAD
+!word dos_RDCHK
 !word dos_UNITCHK
 !word dos_UNITSET
 !word dos_UNITNUM

src/dos_m65/dos_rdchk.s

@@ -0,0 +1,24 @@
+
+;
+; Preload RAM disk image
+;
+
+
+dos_RDCHK:
+
+	; Before the start make sure memory content is not damaged
+
+	jsr dos_MEMCHK
+	bcc @ok
+	lda #$FF
+	jmp dos_EXIT_SEC_A
+
+@ok:
+	jsr dos_ENTER
+
+	lda RD_MSG              
+
+	ldx #$FF                 ; reset the message after it gets displayed
+	stx RD_MSG
+
+	jmp dos_EXIT_CLC_A

src/dos_m65/unit_ramdisk/unit_rd_init.s

@@ -37,6 +37,8 @@ unit_rd_init_test_ram:                 ; non-destructive ATTIC/CELLAR RAM test
 	dex
 	bpl @2
 
+	stx RD_MSG                         ; $FF - mark no message to be displayed
+
 	; For the start, mark extended RAM as not present
 
 	stx RD_STARTSEG                    ; by default $FF, to mark no RAM disk

src/dos_m65/unit_ramdisk/unit_rd_preload.s

@@ -12,7 +12,7 @@ unit_rd_preload:
 	; Check if RAM disk is enabled (should be disabled if no Hyper RAM is present)
 
 	lda UNIT_RAMDISK
-	+beq @error_no_ramdisk
+	+beq unit_rd_preload_err_common_noclose
 
 	; Select SD card buffer
 
@@ -139,6 +139,9 @@ unit_rd_preload:
 	lda #$00                           ; temporary storage needs to be restored to 0
 	sta __stoptrack
 
+	lda #$00                           ; set message to OK
+	sta RD_MSG
+
 	rts
 
 
@@ -149,40 +152,26 @@ unit_rd_preload:
 
 @error_wrong_size:
 
-	jsr unit_rd_preload_err_common
-
-	; XXX set error information
-
-	rts
+	lda #$01
+	jmp unit_rd_preload_err_common
 
 @error_too_large:
 
-	jsr unit_rd_preload_err_common
-
-	; XXX set error information
-
-	rts
+	lda #$02
+	jmp unit_rd_preload_err_common
 
 @error_not_found:
 
-	jsr unit_rd_preload_err_common_noclose
-
-	; XXX set error information, put 0 to __stoptrack
-
-	rts
-
-@error_no_ramdisk:
-
-	jsr unit_rd_preload_err_common_noclose
-
-	; XXX set error information, put 0 to __stoptrack
-
-	rts
+	lda #$03
+	sta RD_MSG
 
+	jmp unit_rd_preload_err_common_noclose
 
 
 unit_rd_preload_err_common:
 
+	sta RD_MSG                         ; set code for startup screen
+
 	lda #$20                           ; dos_closefile
 	sta HTRAP00
 	+nop